1. Field of the Invention
The present invention relates to the healing of wounds and, more particularly, but not by way of limitation, to an apparatus for closing wounds that is compact, self-contained, and includes a disposable wound fluids canister and a porous pad, which is biocompatible with the wound tissue to facilitate the healing of wounds, but does not adhere to the healing tissue.
2. Description of Related Art
Wound closure involves epithelial and subcutaneous tissue adjacent to the wound migrating towards the center of the wound until it closes. Unfortunately, closure is difficult with large wounds or wounds that have become infected. In such wounds, a zone of stasis (i.e. an area in which localized swelling of tissue restricts the flow of blood to the tissues) forms near the surface of the wound. Without sufficient blood flow, the epithelial and subcutaneous tissues surrounding the wound not only receive diminished oxygen and nutrients, but are also less able to successfully fight bacterial infection and, thus are less able to close the wound naturally. Such wounds have presented difficulties to medical personnel for many years.
The most common technique for closing open wounds has been the use of sutures or staples. Although such mechanical closure techniques are widely practiced and often effective, they suffer a major disadvantage by providing tension on the skin tissue adjacent the wound. That is, the tensile force required to achieve closure using sutures or staples causes very high localized stresses at the suture or staple insertion point. Such stresses commonly result in the rupture of the tissue at those points, which can eventually cause dehiscence in wounds, providing additional tissue loss.
Moreover, some wounds harden and inflame to such a degree due to infection that closure by stapling or suturing is not feasible. Wounds not reparable by suturing or stapling generally require prolonged hospitalization with its attendant high cost, and major surgical procedures, such as grafts of surrounding tissues. Examples of wounds not readily treatable with staples or sutures include large, deep, open wounds; decubitus ulcers; ulcers resulting from chronic osteomyelitis; graft site wounds; and partial thickness bums that subsequently develop into full thickness bums. The use of skin grafts in these situations can result in the encapsulation of bacteria and other impurities.
One solution to the problem of non-healing wounds has been demonstrated by applying a continuous negative pressure to the wound over an area sufficient to promote migration of epithelial and subcutaneous tissue toward the wound. A porous pad or other manifolding device may be used to distribute reduced pressure to the wound. The porous pad typically contains cells or pores that are capable of distributing reduced pressure and channeling fluids that are drawn from the wound. One drawback, however, to current designs is that new tissue growth may easily penetrate the cells or pores and effectively attach the pad to the wound. Upon removal of the pad from the wound, any tissue in-growth that has occurred must be physically separated from the pad. Typically, the pad removal involves tearing of new tissue, which not only disrupts the healing process but also may cause discomfort to the patient.